Is 30 degrees hot enough for a laundry wash? Microban thinks not. The company says that mould and odour issues resulting from the widespread adoption of 30 and 40 degree laundry washing could be causing problems with removing bacteria from clothes.

Paul McDonn, managing director at Microban Europe said that a laundering temperature of 60 degrees for 15 minutes is needed to kill the majority of bacteria and also to clean the machine to prevent the build up of mould and odour.

"There are some undeniably strong energy saving arguments for low temperature washing, the fact is that repeated laundering of home textiles at 30 or even 40 degrees is just not hot enough to kill the vast majority of bacteria," McDonn said. While most of these are harmless, he continued, some aren't. These include E-coli, which some research has suggested could accumulate over time.

Although detergent producers say that their products will be effective at 30 degrees, studies have been carried out which show that washing at lower temperatures may only kill 6% of dust mites, potentially causing problems for those sensitive to allergens.

The environmental arguments for washing at low temperatures are compelling, however. According to the detergent producer Ariel, washing at 30 degrees instead of 60 could save enough carbon monoxide to fill four million double-decker buses and a typical household can save around £10 a year by making the switch.